固体高分辨NMR研究PPU/PMAs,AB—交联聚合物中的分子运动和相容性(英文)

STUDY OF THE MOLECULAR MOTION AND PHASE BEHAVIORS IN PU/PMAs AB-CROSSLINKED POLYMERS BY HIGH RESOLUTION SOLID STATE NMR

本文使用固体高分辨NMR测量了PPU/PMAs,AB-交联聚合物中PPU的侧甲基的^(13)C自旋-晶格弛豫时间(T_1)。使用内旋转运动的平均谱密度函数分析了PPU侧甲基的内旋转和PMA的侧基的多重内旋转运动。结果表明PMA中的侧基距主链越远,其旋转速度越快并且PPU侧甲基的内旋转速度随ABCP中PMA侧链长度增加而变快。还使用质子的T_(1ρ)和T_2及自旋扩散研究了体系的相容性和相行为。得到了有关相应尺度下的每相的组成和软相微区尺度的信息。

The internal rotation of side chain in AB-crosslinked polymer(i.e.ABCP) based on the prepolymer of polypropyl oxide urethane (PPU) and polymethacrylates (PMAs) was studied by high resolution solid state NMR by means of 13C spin-lattice relaxation time, T1 . The 13C T1 values were analyzed by using the average spectral density function for nth internal rotation. The results show that the longer the distance between the main chain and the side chain, the faster the rotation of the side group in PMAs and the rotation of the side -CH3 group in PPU becomes faster as the glass temperature of PMA decreases. The phase behavior and the compatibility between the two components were also studied by using 1H T1ρ, 1H T2 and proton spin diffusion measurement. Information about the composition of each phase in corresponding scale and the domain size of the soft phase were obtained.